If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

All dynos are not created equal. One 'rule of thumb' so to speak on automotive forums is that the Mustang dyno reads lower than the Dynojet. In most cases, that is absolutely true. Take this E92 M3 modified by VAC Motorsports for instance. The car has an Active Autowerke tune, Fabspeed cat bypass, Fabspeed X-pipe, and Fabspeed mufflers. What does it put out on VAC's Mutang Dyno? 334 horsepower to the wheels. And on a Dynojet? 390 wheel horsepower in STD correction.

That's a spread of 56 wheel horsepower for the same car with the same mods, significant. Just changing the correction on the Dynojet to SAE changes the numbers to 378 horsepower to the wheel. 12 horses less than in STD correction on the same dynojet and 44 horsepower more than on the Mustang dyno. The next time one is comparing dyno results remember that the numbers can very based on the dyno, conditions, and correction and the same car and show very different numbers due to this.

Just more evidence supporting the fact that you should try to always get numbers from the same dyno & focus on the gains made. Sick of people saying "your numbers are no good because they're not off a DynoJet".

Mike -- Now that you guys have put out more info on the VAC S65 stroker builds, is this customer looking into it? Def seems more appropriate building a stroker than bolting on a s/c for a dedicated track car.

I think mustang dynos are garbage for this very reason. A horsepower is a horsepower is a horsepower... The company should be removed from this earth. Oh, lets calculate a horsepower differently and start a dynamometer company.

I am kidding of course, but not kidding at the same time. For the reason they read low I have posted about, but because of that they suck for 99% of the cases.

^ Not sure you understand the difference of load-based versus interia based dynos and how they calculate horsepower.

For tuning a vehicle a Mustang dyno or load cell based system (Mainline, Maha, Dyno Dynamics, Dynapack) will allow the tuner to do much much more. It is the preferred machine for MANY successful companies. I love when people try to do steady-state or from scratch standalone tuning on a older dynojet dyno and then the car drives like total garbage on the street. The newer load cell based dynojets still don't do everything the Mustang can do either.

I respectfully disagree. Although the mustang dynos do not produce the hero dyno sheets we all want our Mom's to place proudly on the fridge - the Mustang dyno cannot be beat for tuning (partial load especially) and driveability.

Just more evidence supporting the fact that you should try to always get numbers from the same dyno & focus on the gains made. Sick of people saying "your numbers are no good because they're not off a DynoJet".

Mike -- Now that you guys have put out more info on the VAC S65 stroker builds, is this customer looking into it? Def seems more appropriate building a stroker than bolting on a s/c for a dedicated track car.

It's just that a dynojet has the largest base of reference so it's most convenient if you want to the paper comparison.

^ Not sure you understand the difference of load-based versus interia based dynos and how they calculate horsepower.

For tuning a vehicle a Mustang dyno or load cell based system (Mainline, Maha, Dyno Dynamics, Dynapack) will allow the tuner to do much much more. It is the preferred machine for MANY successful companies. I love when people try to do steady-state or from scratch standalone tuning on a older dynojet dyno and then the car drives like total garbage on the street. The newer load cell based dynojets still don't do everything the Mustang can do either.

I respectfully disagree. Although the mustang dynos do not produce the hero dyno sheets we all want our Mom's to place proudly on the fridge - the Mustang dyno cannot be beat for tuning (partial load especially) and driveability.

Tuners love them but from what I understand the highest quality load based dyno for tuning is the dyno dynamics due to the options. The tuners should be able to shed more light.

^ Not sure you understand the difference of load-based versus interia based dynos and how they calculate horsepower.

For tuning a vehicle a Mustang dyno or load cell based system (Mainline, Maha, Dyno Dynamics, Dynapack) will allow the tuner to do much much more. It is the preferred machine for MANY successful companies. I love when people try to do steady-state or from scratch standalone tuning on a older dynojet dyno and then the car drives like total garbage on the street. The newer load cell based dynojets still don't do everything the Mustang can do either.

I understand completely. However, they shouldn't call their rating a horsepower if it's not one is all I mean. From a purely mathematical/physics perspective, this shouldn't differ from machine to machine in a perfect world. That's all I mean. I understand fully the diferences - I have posted about this before... It makes things very confusing when you cannot say - my car makes X HP when it means nothing unless you quantify X with "on this dyno at this location". Again, a perfect world. Just because a mustang dyno is using eddy currents and one uses a fixed mass drum doesn't make the definition of a HP any different.

However, I completely get your point - they may be more helpful than another dyno when looking at how the car will react in the real world. I am just talking about SAE rated HP though - I feel this shouldn't change...

Read the story of how the dynojet rating of HP was started back when they were created and you will see how drastically unscientific it was.

Originally Posted by inlineS54B32

I understand completely. However, they shouldn't call their rating a horsepower if it's not one is all I mean. From a purely mathematical/physics perspective, this shouldn't differ from machine to machine in a perfect world. That's all I mean. I understand fully the diferences - I have posted about this before... It makes things very confusing when you cannot say - my car makes X HP when it means nothing unless you quantify X with "on this dyno at this location". Again, a perfect world. Just because a mustang dyno is using eddy currents and one uses a fixed mass drum doesn't make the definition of a HP any different.

However, I completely get your point - they may be more helpful than another dyno when looking at how the car will react in the real world. I am just talking about SAE rated HP though - I feel this shouldn't change...

Tuners love them but from what I understand the highest quality load based dyno for tuning is the dyno dynamics due to the options. The tuners should be able to shed more light.

My experience is the opposite, while a quality machine I found significant variation from day to day (same stock car going up or down 30hp with no changes) with a Dynamics. I didn't install it or setup the config file in all fairness though. I find Mustangs amazing though. It will be our next purchase.

My experience is the opposite, while a quality machine I found significant variation from day to day (same stock car going up or down 30hp with no changes) with a Dynamics. I didn't install it or setup the config file in all fairness though. I find Mustangs amazing though. It will be our next purchase.